1. Field of the Invention
The present invention relates to a method of manufacturing a terminal, which terminal is applied to a connector housing constituting a connector and soldered to a board while projected from the connector housing when the terminal is attached to the connector housing.
2. Description of the Related Art
For example, a surface-mount connector (hereinafter also referred to as SMT connector) and the like are mounted on the board of an electronic device or an electronic circuit by soldering.
Some of the SMT connectors include a connector housing which is formed in a substantially rectangle box, a lower-level terminal (group of terminals), and an upper-level terminal (group of terminals) attached to a side face of the connector housing. The lower-level terminal and the upper-level terminal are inserted into two-level (upper and lower) mounting holes provided in the side face of the connector housing.
In the state in which the lower-level terminal and the upper-level terminal are attached into the mounting holes of the connector housing, the lower-level terminal and the upper-level terminal are projected outward from the side face of the connector housing and bent downward (toward the board side), with front-end portions of the lower-level terminal and the upper-level terminal being bent along an upper surface of the board. The front-end portion of the lower-level terminal is separated from the connector housing. The front-end portion of the upper-level terminal is also separated from the connector housing but positioned at the opposite side, with respect to the connector housing, to the front-end portion of the lower-level terminal.
A solder fillet is formed in a bending portion, on the base end side, of the front-end portion of each terminal, and a shape of the soldering fillet influences soldering strength. Further, in the above mounting state, it is necessary that a solder bridge is not generated between the terminals.
Therefore, whether or not the solder fillet is properly formed and whether or not each terminal is mounted while the solder bridge does not exist are confirmed by visual inspection or an inspection apparatus utilizing image processing and the like (appearance inspection).
However, in the SMT connector, the front-end portions of the upper-level terminal and the lower-level terminal are provided outward with respect to the connector housing, and the solder fillet is formed so as to be hidden in the back sides of the upper-level terminal and the lower-level terminal. Therefore, in the configuration in which the plural upper-level terminals and the plural lower-level terminals are provided in parallel, sometimes the appearance inspection is difficult to perform.
In particular, the solder fillet of the lower-level terminal, which is located closer to the connector housing than the upper-level terminal, is positioned so as to be hidden by the upper-level terminal, and the appearance inspection thereof is more difficult to perform than in the case of the solder fillet of the upper-level terminal. Further, if the appearance inspection of the solder fillet of the lower-level terminal can be performed, when formation of the solder bridge is detected, the solder bridge cannot be removed.
In order to solve the above problem, for example, there is disclosed Japanese Patent Application Laid-Open (JP-A) No. 2001-110491. In JP-A No. 2001-110491, a center position in a width direction of a portion exposed outward from the connector housing, of the upper-level terminal, is displaced by a predetermined amount (for example, a quarter of an array pitch) in one way of the width direction from the center position in the width direction of a female-terminal fitting portion of the upper-level terminal; the center position in the width direction of a portion exposed outward from the connector housing, of the lower-level terminal, is displaced by a predetermined amount (for example, a quarter of the array pitch) in the other way of the width direction from the center position in the width direction of a female-terminal fitting portion of the lower-level terminal; whereby the front-end portion of the lower-level terminal and the front-end portion of the upper-level terminal are alternately arrayed in a line.
However, in JP-A No. 2001-110491, it is necessary that a lower-level terminal dedicated part is used for the lower-level terminal and an upper-level terminal dedicated part is used for the upper-level terminal. Therefore, in order to produce these terminals, there is a problem that different dies are required for the lower-level terminal and the upper-level terminal, respectively.